ul {
  width: 100%;
  height: 60px;
  position: fixed;
  left: 0;
  bottom: 0;
}
ul li {
  width: 25%;
  height: 60px;
  float: left;
  text-align: center;
  background: #ccc;
  line-height: 60px;
}
ul .active {
  background: #58bc58;
}